DE102017223536A1 - Punching buffer for attachment to a lower or upper die part of a punching device, lower or upper die part, punching device - Google Patents

Abstract

The invention relates to a punching buffer (1) for attachment to a tool lower part or upper part (11) of a punching device (100), comprising at least one spring device (2) for cushioning a punching movement of an opposing tool part (12) in the punching direction (B). and a stop (3) for the opposite tool part (12), wherein the spring device (2) projects beyond the stop (3) counter to the punching direction (B). Furthermore, the invention relates to a Werkzeugunter- or upper part (11) with such a punching buffer (1) and a punching device (100) with such a punching buffer (1).

Description

The invention relates to a punching buffer for attachment to a Werkzeugunter- or - upper part of a punching device, a Werkzeugunter- or -obererteil and a punching device.

In a punching device, as used for example in the production of stamped sheet metal parts and / or sheet metal stamped bent parts, an upper tool, such as a punch or a punch holder, relative to a lower tool part, such as a die or a die holder, moves against a stop. If the upper part of the tool rebounds from the stop, the tool can be damaged and the tool and machine wear out faster. Furthermore, the punching process can be performed incomplete or incorrect, resulting in faulty and unstable products.

The object of the invention is consequently to provide a solution with which the process stability can be increased, the tool wear can be lowered and the reject rate can be reduced.

This is achieved by a punching buffer for attachment to a Werkzeugunter- or upper part of a punching device, comprising at least one spring means for cushioning a along a direction for Werkzeugunter- or -obererteil directed punching movement, and a stop, wherein the spring means the stop against the punching direction surmounted.

Due to the fact that the spring device projects beyond the stop, the spring device first comes into contact with the complementary tool part when it moves towards the lower or upper part of the tool. In the course of the movement, the spring device springs. As a result, the machine is biased so that the bearing clearance is reduced. The punching process becomes more accurate. The spring device also dampens the impact of the tool parts on each other. The punching movement is therefore better defined and the risk of defective products is reduced.

The invention further comprises a tool lower or upper part for a punching device comprising at least one punching buffer according to the invention.

Furthermore, the invention comprises a stamping device comprising at least one stamping buffer according to the invention.

The solution according to the invention can be further improved by the following, advantageous and arbitrarily combinable embodiments and further developments.

The stop can be designed to be rigid in order to be as stable as possible. In particular, the stop can be virtually non-deformable at least in the punching direction by the forces occurring during punching.

In a particularly space-saving configuration, the stop can be arranged, at least partially, in the spring device or surrounded by the spring device or the spring device can be arranged, at least partially, in the stop or surrounded by the stop.

In order to keep the punching buffer and thus the entire punching device in the punching direction particularly compact, the length of a supernatant may be less than 10% of the length of the stop in the punching direction. Preferably, the protrusion, which may be defined as the distance between the outermost part of the stopper and the outermost part of the spring device, that is the furthest from the tool bottom or upper part, is less than 5%, preferably less than 3% or 2%. ,

It can be used in particular spring devices that have a high spring constant, so even at a low deflection record a high force.

In a particularly compact embodiment, the punching buffer can be designed in the form of a pin or column. In particular, the punching buffer may be substantially rotationally symmetrical. This can result in the forces in the punching buffer being distributed substantially symmetrically. Preferably, the stop and the spring device are rotationally symmetric and coaxial. In particular, one of the two can be arranged in the other. As a result, a particularly compact design is possible.

In order to allow a safe movement and avoid tilting, the stop can form a guide for the spring device.

In an advantageous embodiment, the spring device can have a spring element and a transmission element resting against the spring element. The transmission element is preferably located on the end of the spring element facing away from the lower or upper part of the tool. The transmission element may have a preferably planar contact surface, where it comes into contact with the opposite tool part. In such a contact, it may be the force of the opposite tool part to the Transfer spring element. The transmission element can be configured, for example, disk-shaped or sleeve-shaped. The stop can simultaneously serve as a guide for the transmission element and, for example, be at least partially enclosed by the transmission element.

In a further advantageous embodiment, the stop may have a stop portion with a stop face for the opposite tool part and a guide portion for guiding the spring means, wherein the guide portion between the stopper portion and a Befestigungsigungsseitigem end to which the punching buffer on the lower tool or upper part is attachable , is arranged. Such a configuration may, for example, be compact in a transverse direction that is transverse to the punching direction. The abutment portion may be from a free end to the side remote from the Werkzeugunter- or - top part of the stop. The guide portion may be formed by a lateral surface of the stop.

A particularly simple embodiment is possible if the spring device comprises or has a helical spring. The coil spring, for example, record a pin-shaped stop.

In an alternative embodiment, the spring device may comprise or comprise a plate spring. Disc springs usually have a high spring constant, so that even a slight compression or deflection can lead to a high bias voltage. In particular, the spring device may also have a package of disc springs in order to achieve a desired spring stiffness or spring characteristic.

Several spring elements may be present and used, for example, serially, i. be arranged in the punching direction one behind the other. In an alternative embodiment, a plurality of spring elements may also be connected in parallel, i. be arranged side by side with respect to the punching direction.

In a further embodiment, the spring device may comprise a rubber-elastic element, which may be designed in particular solid. For example, rubber elastic members may be less susceptible to failure or pollution damage than resilient members.

In order also to rebound, i. When the spring device springs back from the compressed state to achieve a good movement characteristic, the stop may comprise or comprise a stop surface for a rebound of the spring device. Such a stop surface may in particular point in the punching direction. It can be perpendicular to the punching direction to allow a precise definition of the movement and to prevent lateral deflection in a hitting the spring device to the stop. On the spring device, in particular on the transmission element, a corresponding counter-stop surface may be present, which cooperates with the stop surface. In the power-free state of the punching buffer stop surface and counter-stop surface can be against each other in particular under bias of the spring means or pressed against each other.

In a further advantageous embodiment of the punching buffer may comprise a fastening element for repeatedly detachable attachment of the punching buffer to the lower tool part. As a result, the punching buffer can be exchanged for repair purposes, for example. Further, for example, an element of the punching buffer, such as a spring member, may be exchanged.

The fastening element can be surrounded by the stop and / or the spring device. This makes it well protected. On the other hand, a compact design is possible.

Advantageously, the stop has a channel for the fastening element. As a result, attachment of the stopper may be possible in a simple manner.

If the channel penetrates the stop along the punching direction, a particularly secure configuration may be possible since the channel can not be laterally deformed when the tool top part is hit.

To make the stop as hard and long-term stability, the material of the stop may include or have an optionally hardened tool steel.

In the following, the invention will be explained in more detail by way of example with reference to advantageous embodiments with reference to the drawings. The illustrated advantageous developments and refinements are each independent of each other and can be combined with each other, depending on how this is necessary in the application.

• 1 eine schematische Seitenansicht eines Stanzpuffers zusammen mit einem Werkzeugunterteil und einem Werkzeugoberteil;
• 2 der Stanzpuffer aus 1 an einem Werkzeugunterteil in einer schematischen, teilweise geschnittenen Seitenansicht;
• 3 eine schematische, teilweise geschnittene Perspektivansicht des Stanzpuffers aus 1 und 2 an einem Werkzeugunterteil; und
• 4 eine Darstellung der bei Verwendung des Stanzpuffers aus 1 auftretenden Kraft.

Show it:

• 1 a schematic side view of a punching buffer together with a lower tool part and a tool upper part;
• 2 the punching buffer off 1 on a tool lower part in a schematic, partially sectioned side view;
• 3 a schematic, partially sectioned perspective view of the punching buffer 1 and 2 on a tool base; and
• 4 a representation of when using the punching buffer 1 occurring force.

In the 1 to 3 is an embodiment of a punching buffer 1 shown. It is at a mounting end 15 which also acts as a proximal end 16 can be designated on a tool base 11 mounted a punching device not shown in detail. In 1 she is together with a counter element 13 that with the punch buffer 1 interacts, and that on a tool shell 12 is attached, shown. During punching, the upper part of the tool moves 12 along a punching direction B on the lower tool part 11 to. The tool shell 12 can be considered as a stamp or as a stamp holder (plate). The lower part of the tool 11 may accordingly be a die or a die holder. The parts to be produced are not shown in detail and are typically located away from the punching buffer 1 , The punching buffer is shown by way of example only as attached to the tool base. It can also be attached without modifications to the upper part of the tool.

The punching buffer 1 serves to catch the upper part of the tool 12 , The punching buffer has this feature 1 via a spring device 2 for cushioning one along the punching direction B extending punching movement. The spring device 2 takes part of the kinetic energy of the tool shell 12 and slows it down. Furthermore, the punching buffer has 1 about a stop 3 to which the counter element 13 after a short spring travel of the spring device 2 strikes.

So that the spring device 2 before the stop 3 with the counter element 13 comes into contact, dominates the spring device 2 the stop 3 against the punching direction B , One at a distal end 17 that the fastening-side end 15 opposite, lying stop surface 34 of the stop 3 lies further in the punching direction B as a contact surface 24 the spring device 2 ,

The stop 3 is rigid. It is made of a solid piece of material, for example tool steel.

One along a longitudinal direction L the punching buffer 1 measured length L1 of a supernatant can be compared to the total length L2 the punching buffer 1 which are also along the longitudinal direction L is measured, be low. For example, it may be less than 10% of the total length L2 be. In the example shown, it is only about 1.5% of the total length L2 , The longitudinal direction L runs parallel to the punching direction B ,

In the embodiment shown, the stop 3 in the spring device 2 arranged. He is in an interior 50 the spring device 2 ,

The punching buffer 1 is in the form of a pillar or a pin 52 educated. The punching buffer 1 is substantially rotationally symmetrical about a rotation axis R. Both the spring device 2 as well as the stop 3 are rotationally symmetric about the common axis of rotation R and thus coaxial.

The spring device 2 includes a spring element 21 and one on the spring element 21 adjacent transmission element 22 , At the contact surface 24 of the transmission element 22 becomes the force of the counter element 13 introduced and to the spring element 21 transfer.

The spring element 21 includes a package 81 of cup springs 8th , which are connected in series, ie in the punching direction B lie one behind the other. Disc springs 8th can at an already small deflection in the punching direction B to absorb a great deal of energy.

The stop 3 forms a guide for the spring device 2 , For this purpose, it has particular guide surfaces 31 at a guide section 33 on, for guiding the transmission element 22 along the punching direction B serve. The guide section 33 lies between a stop section 32 with the stop surface 34 for the counter element 13 and the mounting end 15 or proximal end 16 , The stopper section 32 is in a recess 39 of the transmission element 22 the spring device 2 arranged to save space.

To rebound the spring device 2 ie if the counter element 13 again against the punching direction B from the punch buffer 1 moved away, the spring device 2 at the punch buffer 1 to hold, has the transmission element 22 over a counter-attack surface 27 that with a stop surface 37 of the stop 3 interact. The stop surface 37 shows opposite to the stop surface 34 for the counter element 13 , The stop surface 37 points in the punching direction B , It runs perpendicular to the punching direction B ,

In alternative embodiments, the spring device 2 Also have at least one coil spring and / or plate spring or at least one rubber-elastic element.

To the punching buffer repeatedly on the lower tool part 11 attach and detach from this, points the punching buffer 1 a fastener 60 in the form of a screw. The fastener 60 Penetrates the rest of the punching buffer 1 and is in a channel 36 of the stop 3 arranged. The channel 36 runs along the punching direction B so as not to be kinked or narrowed by the forces involved.

A head of the fastener 60 is in a recess 61 of the stop 3 arranged. By loosening the fastener 60 can the punch buffer 1 be exchanged quickly. Furthermore, it can, for example, by an exchange of the spring elements 21 be varied in their spring rate and spring characteristic.

In 4 is shown as the punch buffer 1 from the 1 to 3 acts on the movement during punching. To the right, the rotation angle of an eccentric drive is plotted, whereby at 180 °, the maximum deflection of the upper tool part 12 is achieved. Towards the top is a force measured along with a piezo element along the punching direction B applied. One can see a curve with essentially a single large deflection and smooth transitions. In contrast to the previous solutions, for example, with a hard stop, which causes a rebound and thus two deflections, can with the punching buffer shown 1 Such bouncing can be prevented, thereby minimizing the risk of defective products. At the same time any play is removed from the punching device by the tensioned spring, so that the punching process can be performed precisely.

LIST OF REFERENCE NUMBERS

1

punch buffer

2

spring means

3

attack

11

Tool part

12

Upper die

13

counter-element

15

mounting end

16

proximal end

17

distal end

21

spring element

22

transmission element

24

contact area

27

counterstop

31

guide surface

32

stop section

33

guide section

34

stop surface

36

channel

37

stop surface

39

recess

50

inner space

52

spigot

60

fastener

61

recess

80

Belleville spring

81

package

100

punch

B

punching direction

L

longitudinal direction

L1

length

L2

length

R

axis of rotation

Q

transversely

Claims (15)

Punching buffer (1) for attachment to a tool lower part (11) of a punching device (100), comprising at least one spring device (2) for cushioning along a punching direction (B) punching movement of a tool upper part (12), and a stop (3) for the Tool upper part (12), wherein the spring device (2) projects beyond the stop (3) counter to the punching direction (B). Punching buffer (1) after Claim 1 , wherein the stop (3) in the spring device (2) or the spring device (2) in the stop (3) is arranged. Punching buffer (1) after Claim 1 or 2 , wherein the spring device (2) has a spring element (21) and a on the spring element (21) fitting transmission element (22). Punching buffer (1) after Claim 3 , wherein the transmission element (22) the ring (3) surrounds and projects beyond. Punching buffer (1) according to one of Claims 1 to 4 , wherein the stop (3) forms a guide for the spring device (2). Punching buffer (1) according to one of Claims 1 to 5 in that the stop (3) has a stop section (32) with a stop surface (34) for the tool upper part (12) and a guide section (33) for guiding the spring device (2), the guide section (33) being located between the stop section (32 ) and a fastening-side end (15) on which the punching buffer (1) on the lower tool part (11) attachable, is arranged. Punching buffer (1) according to one of Claims 1 to 6 , wherein the spring device (2) comprises at least one coil spring and / or plate spring and / or at least one rubber-elastic element. Punching buffer (1) according to one of Claims 1 to 7 , wherein the stop (3) comprises a stop surface (37) for a rebound of the spring device (2). Punching buffer (1) according to one of Claims 1 to 8th , wherein the punching buffer (1) comprises a fastening element (60) for the repeatedly detachable attachment of the punching buffers (1) to the tool lower part (11). Punching buffer (1) after Claim 9 , wherein the fastening element (60) of the stop (3) and / or the spring device (2) is surrounded. Punching buffer (1) according to one of Claims 9 or 10 , wherein the stop (3) has a channel (36) for the fastening element (60) Punching buffer (1) after Claim 11 wherein the channel (36) penetrates the stopper (3) along the punching direction (B). Punching buffer (1) according to one of Claims 1 to 12 , wherein the material of the stopper (2) comprises a tool steel. Tool lower or upper part (11) for a punching device (100), comprising at least one punching buffer according to one of Claims 4 to 13 , Punching device (100) for punching sheet material, comprising at least one punching buffer (1) according to one of Claims 4 to 13 ,

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